Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J7/00—Details not provided for in the preceding groups and common to two or more basic types of discharge tubes or lamps
  • H01J7/14—Means for obtaining or maintaining the desired pressure within the vessel
  • H01J7/18—Means for absorbing or adsorbing gas, e.g. by gettering
  • H01J7/183—Composition or manufacture of getters
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C27/00—Alloys based on rhenium or a refractory metal not mentioned in groups C22C14/00 or C22C16/00
  • C22C27/02—Alloys based on vanadium, niobium, or tantalum

Definitions

• Getter materials have been used for many years in industry and in the laboratory, for example for absorbing harmful residual gases from vacuum pipes, apparatus filled with noble gas, vacuum systems and the like. For these applications it is frequently necessary to activate the getter material at relatively low temperatures (ideally below 500° C.) in order to avoid harmful thermal effects on the housing walls.
• the customarily used getter materials made of zirconium or zirconium-aluminium alloys require activation temperatures of 700°-900° C. and, in the most favorable case, of only partial activation, of about 500°-700° C.
• getter material which has good soption properties and can be activated at very low temperatures.
• the alloys are prepared in a manner known per se by melting together the alloy constituents or appropriately selected prealloys under protective gas, by first of all in a manner known per se preparing a melt from the higher-melting constituents and then adding the lower melting constituents, in order to minimize the rates of evaporation. To reduce the oxygen content of the alloy, the melt is then deoxidized in conventional manner by addition of known deoxidizing agents, lanthanum, misch metal and the like.
• the solidified melt is then pulverized under protective gas.
• the alloy is capable of absorbing large amounts of hydrogen at about room temperature and of rereleasing the amounts at temperatures of about 100°-150° C. This absorption-desorption process leads to a comminution of the alloy particles, so that by repeatedly loading and unloading the alloy with hydrogen the particle size of the alloy can be reduced to less than 1 um.
• the resulting large surface area combined with short diffusion paths is responsible for a particularly powerful absorption effect per gram of the getter material.
• the getter material can likewise be activated by loading and unloading the alloy with hydrogen, for example by introducing the hydrogen-loaded getter material into the operating space and then removing the hydrogen by pumping at moderate temperatures between room temperature and about 150° C., exceptionally however at even higher temperatures.
• the getter material thus activated has an excellent absorption capacity for nitrogen, water, oxygen, carbon oxides, hydrogen and the like.
• it is also possible to use the hydrogen-loaded getter material for example if the release of small amounts of hydrogen is not critical or the operating atmosphere is H 2 , since the absorption capacity for the other gases is barely affected by the hydrogen content, if at all.
• Alloys which have been found to be particularly suitable are alloys of the formula TiV 1 .8 Fe 0 .2, TiV 1 .6 Fe 0 .2 Mn 0 .2 and in particular TiV 1 .6 Fe 0 .4, TiV 1 .5 Fe 0 .4 Mn 0 .1, and TiV 1 .6 Fe 0 .2 Cr 0 .1 Mn 0 .1.
• the greater material described have remarkably low absorption pressures of less than 10 -6 mbar and are frequently within the order of 10 -7 -10 -8 mbar.
• the getter materials are particularly inexpensive to prepare, for example using inexpensive ferrovanadium.

Applications Claiming Priority (2)

Publications (1)

Family

ID=6240071

Family Applications (1)

Country Status (5)

Cited By (10)

Families Citing this family (3)

Citations (15)

Family Cites Families (6)

• 1984
  • 1984-07-07 DE DE3425055A patent/DE3425055C1/de not_active Expired
• 1985
  • 1985-06-26 IT IT8521297Q patent/IT1188172B/it active
  • 1985-07-02 GB GB08516713A patent/GB2161182B/en not_active Expired
  • 1985-07-05 US US06/751,972 patent/US4717551A/en not_active Expired - Lifetime
  • 1985-07-05 FR FR8510304A patent/FR2567154B1/fr not_active Expired - Fee Related

Patent Citations (15)

Non-Patent Citations (4)

Also Published As

Similar Documents

Legal Events